The invention relates to the field of converters such as inverters, for example those used in uninterruptible power supplies, in particular in high-power uninterruptible power supplies, i.e. with a power generally comprised between about 100 and 500 kVA.
The invention relates more particularly to a converter device enabling an AC voltage VS and current IS to be supplied by filtering pulses obtained on a modulated signal output SM from three substantially DC voltages −U/2, UREF, U/2 available on a reference voltage line REF and on two DC voltage inputs P, N of opposite signs respectively from two switching units UC1, UC4, each switching unit comprising a switching output S1, S4 to provide pulses having an amplitude varying between the voltage on the input of said switching unit, in a first switched state of said switching unit, and the voltage on said reference voltage line in a second switched state of said switching unit, each switching unit comprising a first switch T1, T4 connected between the input and the switching output S1, S4 of said switching unit to establish said first switched state by turn-on of said first switch, said device comprising a second switch T2, T3, for each switching unit, associated with said switching unit, connected between said switching unit and said modulated signal output to activate said switching unit by turn-on of said second switch.
The invention also relates to an uninterruptible power supply 101 comprising a power supply input 102 on which an AC input voltage is applied, a rectifier 103 connected to said input, two substantially DC voltage lines of opposite signs connected on output of said rectifier, and an inverter 106 connected to said voltage lines of substantially DC voltage and comprising an output 107 designed to supply a secured voltage.